How do children learn complex language?

If you want children to understand what you say, use short, simple sentences and talk about things that they can test against reality. This is the conclusion of research by cognitive psychologist Jun Lai. Defence on 26 February 2013.

Centre-embedded recursion

It is an intriguing mystery how children learn complex linguistic structures, such as centre-embedded recursion, as in The child that the mother held was crying (in this case, The child […] was crying is the clause that is split by the recursion). What puzzles linguists and psychologists alike is the following: how does the young language learner understand that it is not the mother who is crying, but the child? After all, in this sentence, is crying is much closer to the word mother than to the word child.

Testing it against reality

Lai’s research shows that the ‘literal’ distance between the words of a sentence that belong together ('positional distance') is actually not such a problem for the language user. The so-called 'semantic distance' is much more important: what makes sense and what is odd? Take the example of The child that the mother held was crying. The fact that in this sentence, child and was crying are not close together, but separated by that the mother held, is not so important. What is important is that in the verifiable reality it makes more sense for a mother to carry a child than the other way around, as well as the fact that children generally cry and their mothers do not.


This use of the reality to learn/interpret language became apparent in an experiment in which test subjects were supposed to quickly indicate the meaning of complex sentences. Sometimes the words that belonged together were close together and sometimes they were far apart. In some cases, they formed a very natural pair (The dog is barking), in other cases on the contrary, they formed a very odd pair (The dog is laughing). The test showed that test subjects understand sentences such as the example The child that the mother held was crying (short semantic distance – long positional distance) better and quicker than the simpler construction The child carried the mother that was crying (long semantic distance, short positional distance).





Decennia-old discussion  
This research appears against the background of a decennia-old discussion: is linguistic competence a unique innate human competence, as linguist Chomsky has been arguing since the 1950s, or is language learned in the same way as social behaviour (table manners, for instance) or routine behaviour (such as cycling)? These skills can be learned through simple mechanisms such as conditioning, imitation and association. In either case, the fact remains that communication systems in animals are in no way as complex as human language. 

Practical tips

As shown in Lai’s research, user-friendly language use when talking to children learning a language means the following: firstly, use only short and simple sentences, and secondly, talk mostly about observable things that children can test against reality.


The Learnability of Center-embedded Recursion:
Experimental Studies with Artificial and Natural Language
Jun Lai
26 February 2013, 11:15 hours 
Academy Building, Rapenburg 73, Leiden 
Faculty of Social and Behavioural Sciences 
Thesis supervisors: Prof. N.O. Schiller and Prof. B. Hommel

This PhD project was made possible by an Open Competition NWO grant for Dr Fenna Poletiek, who also acted as Lai’s supervisor and co-supervisor.

(21 February 2013)

See also

Studying in Leiden



Last Modified: 26-02-2013